Histology of Digestive System Accessory Glands in Newly Hatched Larvae of Caspian Kutum, Rutilus frisii kutum

Inroduction & Caspian Sea is an enclosed ecosystem, which contains valuable aquatic species. This ecosystem is under the influence of pollutants and environmental factors which put the life of inhabitant species in danger. To investigate the structure and histology of digestive system accessory glands of newly hatched larvae of Caspian Kutum, Rutilus frisii kutum, the larvae of this fish were examined.
Material and First of all, the larvae were fixed in bouin solution and after the common protocol of the histology, 6 μm thick sections were modified and after the staining of haematoxylin and eosin the sections were studied using light microscope.
The accessory glands of digestive system were: liver, hepatopancreas, gall bladder and the yolk sac. Yolk sac was a large structure at the ventral side of the body made of the yolk cells. Liver was made up of hepatocytes which were multidimensional cells sited around the hepatic sinusoids. Bile ducts were observed in liver and ended up in to a gall bladder. At the terminal part of the liver tissue there was a hepathopancreas composed of eosinophilic exocrine cells.
Counclusion:Results of the present study showed that the accessory glands of digestive system in newly hatched larvae of Caspian kutum were totally formed and practical waiting for opening of the mouth to complete the secretory duty of themselves.